Ok, so first I have to make up my mind about whether to purchase the xt or the xti, but then there are so many lenses...I mainly plan on using the picture to take photographs of homes, both inside and out, in order to create virtual tours. I really want a lens with wide angle capabilities in order to capture as large an angle as possible of interior rooms, but I can't have any of that barel (sp) distortion going on because I commonly stitch the photos together and straight lines match up much easier than opposing curves. I also would use the camera to take pictures of the view from a prospective home, which of course requires some telephotic (sp) capabilities. In addition my wife will likely borrow my camera on occasion to take pics of the kiddos etc. Is there a single lens that will accomadate all my needs or will I need to purchase two seperate lenses?

With your fairly stringent requirements my guess is that you will need at least two lenses. As leonak says, the EF-S 10-22mm f/3.5-4.5 USM has to be a strong contender given your requirement for tightly controlled geometry. Check out Gordon's review and video tour. Another possible contender might be the Sigma AF 12-24mm f/4.5-5.6 HSM EX DG which PhotoZone reviewed here. They also did this review of the Canon 10-22mm lens.

For a single lens to complement this, the EF 28-135mm f/3.5-5.6 IS USM (PhotoZone review here) might be worth checking out. If you can run to a three lens solution then read Gordon's Rebel XTi lens upgrade group test for your second lens and then, for your third, consider the EF 70-300mm f4-5.6 IS USM which, according to the PhotoZone review, is a "hidden Canon L lens".

Bear in mind, please, that I own none of the lenses above and my comments are based on reviews done by others. Nevertheless, I hope these ideas get you started with the decision making.

Firstly I would get the XTi/400D over the XT/350D and secondly get the EF-S 10-22mm f3.5-4.5 USM, I have this lens and is absolutely brilliant indoors. Had to take some pictures for a local Hairdressers for their grand reopening a few months ago and this was the only lens I used inside and out, I was gobsmacked as to the amount that I got in and in such a smallish area it's a bit pricey but in my opinion well worth it.

ok im startin to learn now (at least I think so). Now, that I understand the xti is synomynous with the 400d not the 40d am I correct in assuming that if I bought an xti all ef lenses would be incompatible with it, and only ef-s lenses would work?

So....with my purpose in mind is there any need for me to consider purchasing a 40d camera and the available ef lenses that would go along with it?

The EF-S lenses are only compatible with Canon's "cropped sensor" models but as they include the XT, XTi, 40D & 30D and earlier you don't have to worry too much about buying EF-S lenses unless you want to upgrade the camera body later on to a full-frame model like the EOS 5D. EF lenses are compatible with all of Canon's current (EOS) DSLRs.

It's a steep learning curve getting to grips with all these technical terms so don't worry about asking questions. We've all been there! Reading the various camera and lens reviews carefully pays dividends in helping to pick up the "lingo". Have a browse through some of Gordon's reviews which you can find here.

yeh mine is my first dslr and i read a million reviews beforei chose. i was going to get the xti but decided as i was going to be keeping it for a loooonng time id rather get the 30d. i would have liked the 40d but funds wouldnt allow. i went for the canon 10-22 over the sigma for the simple reason that some people have had problms with it and mine was being brought over from the states so i couldnt take it back if i had problems with it.

ok im startin to learn now (at least I think so). Now, that I understand the xti is synomynous with the 400d not the 40d am I correct in assuming that if I bought an xti all ef lenses would be incompatible with it, and only ef-s lenses would work?

No. Both EF and EF-S lenses work with 400D and 40D. In that regard there is no difference between these two cameras.